As a child growing up in rural Arizona, Ina Mapes remembers her mother as a highly discreet woman who rarely expressed her personal feelings except when it came to one particularly incendiary topic: Did Mapes’s father, a raven-haired lawyer, have Native American roots, or did he not? Mapes’s grandmother maintained that he had one-quarter tribal blood. But her mother wanted to hear nothing of it.

“My mother did not approve of Indians, and she insisted that my father was not an Indian,” said Mapes, 77, of Catalina, Ariz. “In those days, it was not a plus to be an Indian, not at all. She said that Granny, my father’s mother, was just making it up and she did not believe it.”

Mapes, a mother of four who volunteers in a clothing bank, is a second cousin to US Senate candidate Elizabeth Warren. The two women, who have never met, share more DNA than most second cousins: Not only were their grandmothers sisters, their grandfathers were brothers. Those brothers — a team of carpenters named Harry and Everett Reed who plied their trade in the Indian Territory that would become the state of Oklahoma — are believed by some family members to have roots in the Delaware tribe. Mapes, who said she was unaware of her cousin’s candidacy until contacted by a reporter, said she does not doubt her heritage.

“I think you are what you are,” said Mapes. “And part of us is Indian.”

Questions about Warren’s roots have continued to shadow her candidacy since the matter erupted in a political firestorm in April. Warren acknowledged that she had identified herself as a minority in a legal directory for nearly a decade, and she was listed as a Native American in federal forms filed by the law schools at Harvard University and University of Pennsylvania where she worked. Warren has never fully explained her assertion of Native American ancestry, and her Republican opponents continue to brand her a liar. Officials from both schools have said that her assertion of ancestry was not a factor in her hiring.

Warren’s extended family has mixed opinions on the Native American question. The stories shared by Mapes, as well as Warren’s brothers and a number of her cousins, echo Warren’s assertion. But other cousins, some of whom also do not know Warren, say they know nothing of Native American blood in the family. According to one family biography, on file at the California State University at Fullerton, one of Warren’s relatives once shot at an Indian.

Warren Campaign

Harry Reed was part Indian, say descendants.

Months after the political flare-up, Warren and some of her family members remain unwilling to provide details on the subject. In a lengthy interview, Warren referred to stories about her roots that she says were frequently told at family gatherings in her native Oklahoma, but declined to share virtually any of them. “I knew it was part of our family,” Warren said. “It was part of what we talked about. . . . It was just part of who we were.”

‘White folks did not want to be identified as Indian whether they were one-eighth or one-half. In a short time, the reverse happened.’

Warren’s family, including cousin Mapes, have no documentation of Native American affiliation, nor is there evidence that they are listed on any official tribal roll. While Senator Scott Brown, Warren’s opponent, has used this to question her truthfulness, many who assert such heritage are unable to document it, according to several scholars. During the late 1800s and early 1900s, many Native Americans did not join tribal rolls for a host of complex reasons, including residency requirements, fear of discrimination, and opposition to land allotment policies.

In the absence of documentation, the family’s link to any Native American tribe is a matter of narrative inheritance or folklore, as Warren puts it. Even if Warren has some degree of Native American blood, it is unclear if it would meet conventional standards of what constitutes a minority.

Warren’s reluctance to talk about it, or to explore possible documentation, reflects the complex questions about biography and childhood memory that have percolated through the bitterly fought race for the Senate seat. Brown has also been said by some members of his family to have embroidered his painful past. One cousin, for example, says he exaggerated episodes of deprivation in his childhood.

David Herring of Norman, Okla., one of Warren’s three brothers, said in an interview that even when he was a child his relatives were reluctant to talk about the family’s Native American heritage because “it was not popular in my family.” Only when he begged his grandparents, said Herring, did they finally explain to him: “Your grandfather is part Delaware, a little bitty bit, way back, and your grandmother is part Cherokee. It was not the most popular thing to do in Oklahoma. [Indians] were degraded, looked down on.”

Warren’s brothers, Don, John, and David Herring, also issued a joint statement supporting their sister. “The people attacking Betsy and our family don’t know much about either. We grew up listening to our mother and grandmother and other relatives talk about our family’s Cherokee and Delaware heritage. They’ve passed away now, but they’d be angry if they were around today listening to all this.”

On the plains of Oklahoma, where many of the nation’s tribes were forcibly relocated in the mid-19th century, the American Indian has long been a dominant cultural force. The very name Oklahoma is derived from the Choctaw word for “red people.” Oklahoma has the second-largest population of American Indians and Alaskan Natives in the United States, with 8.6 percent of its people claiming such heritage in 2010, according to the US Census Bureau. But many local historians believe the number is more likely double that given the widespread mingling of the Native American and Caucasian populations.

As a teenager, Warren’s grandmother, Bethanie “Hannie” Crawford, drove a horse-drawn wagon in 1888 from her native Missouri to the Indian territory that would eventually become Oklahoma, drawn by the prospect of land and opportunity. Several of her then four siblings came with her and several more would be born in the Cherokee Nation, Indian Territory, in the following years, according to the US Census of 1900. The Crawford sisters married the Reed brothers on the same June day in 1893, according to their marriage records. Laura and Everett had one son, Charles Reed, who was born in 1906, the year before Oklahoma became a state. He fathered one daughter, Ina Mapes.

Both the Reeds and the Crawfords are identified as “white” on federal Census forms in the early 20th century that rely upon self-identification. While that may have been a simple statement of fact, they may also have been trying to obscure their ethnicity. At the time, the federal government was attempting to break up reservations by granting land allotments to individual Native Americans, pressing them to assimilate into white society and leave their tribal ways behind. The goal, as one officer bluntly put it, was to “kill the Indian and save the man.” Those who could pass for white — or convince the census taker that they were — sometimes did.

JOSHUA LOTT FOR THE BOSTON GLOBE

Ina Mapes is a second cousin to US Senate candidate Elizabeth Warren. She says her relatives also spoke of Native American blood in the family.

“If someone was not white, they were a little bit less of a citizen,” said Matt Reed, the curator of the American Indian Collections at the Oklahoma Historical Society in Oklahoma City, whose mother was a Pawnee Indian. “If you had darker skin, you were a lesser human. So, if your skin was light enough to pass as not being Indian, then you just passed as white and your life was a lot better off. A lot more people did that than you might think.”

Born and raised in Arizona, Ina Mapes visited her grandmother and other Reed relatives in Okmulgee, Okla., every summer. Her grandmother, by then widowed, often talked about her son’s Indian blood, which she said he inherited from his father, Everett Reed. While Laura Reed was proud of her son’s heritage, Mapes said, her own mother was distinctly not. Both of the older women would independently harangue young Ina on the topic, in part of their ongoing dispute. A lawyer consumed by his practice, Charlie Reed did not weigh in on the matter.

“I was torn between those two women because they did not get along,” said Mapes. “It was two women fighting over this man and his being an Indian.”

Elizabeth Warren said her mother also clashed with her in-laws over the subject of her heritage. Her parents, Donald Herring and Pauline Reed, both of Wetumka, Okla., loved each other very much, Warren said, “but his mother and father did not want him to marry someone who was part Delaware and part Cherokee. And so they eloped. His parents would not let them get married. That is how they put it.”

Herring, 21, and Reed, 19, were married in January 1932 by the minister of what was then the Methodist Episcopal South Church in Holdenville, Okla., according to their county marriage certificate. There is no recording of their marriage in the log book of the church, which is about 20 miles from their residence in Wetumka. The church’s historian, Karen Anderson, suspects the minister acted as a justice of the peace and married the couple in the parsonage.

Days later, the local newspaper, The Wetumka Gazette, ran a notice of their marriage, pointing out that the union of “two of Wetumka’s most popular young people came as a surprise to many of their friends when they returned from Holdenville late Saturday afternoon and announced their marriage.”

Warren said in an interview that she heard of her mother’s Native American blood through a series of conversations the two of them had while Warren played with a favorite set of paper dolls. The dolls included a groom and a bride in a pink wedding dress. One day Warren, then about 7, asked her mother about her own wedding dress, and her mother said she had not had one. When Warren pressed for details, “she said no one came to her wedding at all. This is when I realized something was wrong. . . . That is when she explained.”

Warren said she was informed by others in the family that her mother’s mother “was a little bit Delaware, and her father was more Cherokee.” Told that her brother recalled the opposite, she added, “It might have been the other way around.” Her grandmother, she added, “always talked about PawPaw being a lot more Indian.”

The Cherokee Nation, like many tribes, will only release the names of those on its rolls to those claiming membership. While a spokeswoman for the Delaware Tribe of Bartlesville, Okla., one of several branches of the tribe, said that their roll includes a member with the name of Reed born around the turn of the century, she would not provide additional information. Warren’s campaign declined to request the information from either tribe.

Some among the many descendants of Hannie and Laura Crawford’s siblings — who did not marry Reeds — say they had never heard of Native American blood in the family. Dixie Crawford Hicks, another of Warren’s second cousins and the chairwoman of the Department of Social and Behavioral Science at Faulkner University, a Christian university in Montgomery, Ala., plumbed deep into the family history in writing a biography of her grandfather in 1976. Rosco Crawford, Hannie Crawford’s brother, told Hicks that as a young boy living in the Creek Nation of Indian Territory, the Indians were “pretty mean.” Once, when a Creek was hitting Crawford’s younger brother, their father shot and wounded the Indian, according to her biography, on file at California State University at Fullerton.

Hicks’s father, Clyde Crawford, a first cousin to Warren’s mother, said he had no knowledge of the family having Native American blood, according to Hicks.

So, too, Vivian Renfrow, 99, a first cousin to Warren’s mother living in Tulsa, said she never knew that her aunts Hannie and Laura married men who some believed to have Indian roots. She remembers being fearful of Indians in the years just after statehood, “who would stop by on their horses at night and Daddy would call Mama to get the gun in case they did something, but they never did.”

However, other descendants of Hannie and Laura — those with a direct connection to the Reed brothers — say they were told stories about their Cherokee and Delaware blood similar to those heard by Warren and her brother. Like their cousins, they never questioned the truth of what they were told and apparently made no attempt to document their roots.

Gloria Wysong, a cousin of Warren’s, said in an e-mail that her mother told her that the family’s heritage “was Delaware, but the Delaware and Cherokee merged together. She’d heard the stories from her grandfather who built houses in Indian Territory.” Wysong, who lives in Oklahoma City, and others in the family declined to elaborate.

Robert C. Boraker, a retired journalist and amateur genealogist who said he is Warren’s fourth cousin — their great-great-grandfathers were brothers — said his father often told him that his grandmother, a Crawford, was one-eighth Indian. “It was Cherokee blood,” said Boraker, who lives in St. Albans, England, and publishes a family newsletter that includes the Crawford line. “There was no documentation, but it was what we knew, what we were told.”

Warren’s brother David, eight years her senior, calls the public controversy over the subject “a bunch of baloney.” He remembers relatives cautioning him when he played cowboys and Indians as a child. “My aunts said, ‘Be careful shooting the Indians because some of them are your relatives.’ ” But most shied away from the subject of the family’s heritage, Herring added, because “it wasn’t something you were proud of.”

By the time Warren came of age in the early 1960s, that attitude still prevailed in certain quarters of Oklahoma society. In bars and restaurants outside Oklahoma’s urban centers, signs could still be seen saying, “No Dogs or Indians Allowed.”

While there was greater tolerance in urban centers such as Oklahoma City, Native Americans continued to encounter discrimination and hostility. As Jerry Bread, outreach coordinator for the Native American Studies program at the University of Oklahoma, puts it, “It was not acceptable socially or racially to be an Indian at the time,” said Bread, who is half Cherokee and half Kiowa. “White folks did not want to be identified as Indian whether they were one-eighth or one-half. In a short time, the reverse happened, as there were benefits to be had.”

At the Northwest Classen High School in Oklahoma City that Warren attended, many students had been told stories about their Native American relatives just as Warren said she had. Garrick Bailey, professor of anthropology at the University of Tulsa, who attended school in Oklahoma City in the 1950s, estimates that as many as 50 percent of the students at Classen possibly had Native American blood, based on an informal census taken at his own school.

Bob Hammack was one of them. A member of the class of 1966 along with Warren, Hammack said he is one-16th Cherokee and his wife is one-16th Apache.

His Cherokee grandmother never enrolled, he said, “because she and others were afraid if they gave their name they would be shot.”

Now president of the Oklahoma City advertising agency New West Group, Hammack recalls that while Northwest Classen students studied Oklahoma’s Native American history, few in the class of nearly 1,000 students talked about their personal link to that history, including Warren.

“Indians were just not on the radar screen,” said Hammack. “At the time, it was not relevant, it was not important.” Today, Hammack’s business card sports a large profile of a red Indian chief. Being Indian, he adds, “is cool.”

Suzanne Pope, a friend of Warren’s from the school’s debate team who now lives in San Diego, had similar feelings back in school. Her father, she said, often “dragged out pictures of the Indian squaw, my great-great-grandmother on my father’s side. Word was she was Cherokee, but we could not prove it. Lots of people in Oklahoma have ancestry, but it wasn’t fashionable to put yourself on the tribal rolls.”

For the small handful of students who looked distinctly Native American, the experience was quite different.

David Yeagley, whose mother was Comanche, said that he and his brother Fred, who was a class behind Warren, were routinely teased for their dark hair and skin. When fellow members of the football team did not feel like playing on a hot day, “they’d say, ‘Fred, do a rain dance. Do a few steps for us,’ ” Yeagley said of his brother, who died in 2000.

“Fred did not like that, and he was in fights every other day. Why would you ever bring up being an Indian if you didn’t have to? You’d just get teased or ridiculed,” said Yeagley. “If you were an Indian woman, you were thought of as an easy mark.”

While Warren did not talk to many classmates about her heritage, she loosened up with her friend Katrina Cochran.

As the two drove in Warren’s white MG to the Charcoal Oven drive-in for lunch in their senior year, they would sometimes have a mock debate about who was more “Indian.”

“She talked about her grandmother being a Cherokee, and I talked about how my aunt by marriage was a Choctaw,” said Cochran, an Oklahoma psychologist. “I was making a totally illogical argument, saying I was just as Indian as she was. It was ridiculous because she had the blood and I did not, but it made us laugh.”

When pressed to discuss conversations she may have had with classmates who had similar stories, Warren declined to elaborate. “It was a different time,” she said.

Forty years later, when the subject of Warren’s heritage erupted on the national airwaves, some of her former classmates smirked to hear her say that Native American blood was central to her identity. Few of them, certainly, had ever heard anything of it. But to Cochran, the timing made sense.

“It did not surprise me one bit that Liz was in her adulthood . . . when she began to embrace her heritage,” said Cochran. “In the South of those days, these issues were just not discussed. We are the buckle of the Bible Belt down here.”

Jeremiah Manion and Noah Bierman of the Globe staff contributed to this report. Sally Jacobs can be reached at jacobs@globe.com.